Island



2 Sheets--Sheet.1.

J. HOPE. Pantograph Engraving Machine.

Patented June 7,1881.

HIHWHIIHM FIG.2.

INVE'NTUR'.

WITNESSES.

2 Sheets-Sheet 2.

Pantogra 'ph Engraving Machine.

No. 242,449. Patented lune 7,1881.

I Fig.5

WITNESSES; I'NVENTORI A I @ddwi a m UNITED {STATES PATENT OFFICE.

JOHN HOPE, OF PROVIDENCE, RHODE ISLAND.

PANTOGRAPH ENGRAVlNG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 242,449, dated June 7, 1881.

Application filed July 18, 1879.

To all whom it may concern:

Be it known that I, JOHN Horn, of the city of Providence, county of Providence, and State of Rhode Island, have invented a new and useful Improvement in Pantographs; and I hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying draw ings, forming part of this specification.

This invention has reference to improvements in the stylus or tracing-point of a pantograph; and it consists in the peculiar arrangement by which a perfect circle or. a perfeet wave-line is traced by mechanical means, as will be more fully set forth hereinafter.

In a pantograph the stylus is made by the operator to follow an enlarged design which, by a combination of levers, is traced with diamonds or other cutting devices, on a reduced scale, into the roll or plate, or is marked by suitable markers, on a reduced or enlarged scale, on any surface. VVh'eu accurate circles are to be described, and particularly when a number of circles are made one within the other, the operator is liable to describe these circles irregularly with the stylus, and the pcculiar form of a circle is such that the slightest irregularity will be observed. The same is true of regular wave-lines, which it is very difficult to follow, the operator being liable to produce angles insteadof curves at the sides of the wave-line. To obviate this difficulty and increase the accuracy as well as the capacity of the machine, I secure the stylus to an adjustable slide, which is secured to the guide-arm by a shaft that can be rotated by a handle, or secured in a fixed position, and also arrange the stylus so that it can be connected with a screw or worm which is adjustably secured to a crank, so that the same can be made to describe a circle of any desired diameter, and thereby produce a waving motion of the arm of the pantograph 'of any desired width or pitch.

Figure 1 is aview showing an eccentric worm or screw provided with a handle secured to the table of a pantograph and connected with the arm of the pantograph, so that by turning the worm or screw a wave motion is produced by the arm, which may be transmitted to a roll or other surface by the pantograph. Fig. 2

worm or screw. Fig. 4 is a sectional view of the worm or screw, showing the manner of connectingthe same with the stylus-connectin g arm. Fig. 5 is an end view of a pantograph engraving-machine, showing the stylus connected to the tracer-arm, so that every motion of the tracer-arm will be followed by the stylus.

In the drawings, a is the table of the pantograph, on which the pattern is laid.

I) is the arm for connecting the stylus with the tracer-arm, suitably supported on the table and carrying the tracing-point, so that the motion of the same is transmitted to the tracing point or points by which the figure is marked on the roll or other surface.

0 care the handles by which the operator guides and moves the arm 1).

dis the stylus, which has heretofore been secured to the arm I), the point of the stylus resting on the pattern and enabling the operator to follow the design. In this case the stylus is secured in the slide 0, which slide is secured to the nicely-ground spindle f. The stylus can therefore be set by means of the screw 9 any desired distance from the center of the spindlef.

To the upper part of the spindle the crank it is secured, and when the point of the stylus is now placed on a point in the pattern and the crank h is turned the arm b, carrying the stylus at one'end and connected at the other with the tracer-arm, will describe an accurate circle the radius of which is equal to the distance the point of the stylus is from the vertical axis of the spindle f, and by connecting the slide on the stylus with a screw or worm fixed in the slide e,and provided with athumb-screw, or secured by any other of the well-known adj usting devices, then the stylus can be readily adjusted so as to permit the movement of the arm I) through a circle of any desired diameter by turning the crank, and very elegant and accurate designs or shadin gs of designs can be produced. This is accomplished through the connection of the handle it to the arm b by means of the thumbscrew i, as shown in Fig. 2 in broken lines.

If a wave-line is to be produced, the frame K is secured to the table of the pantograph. It is provided with a screw or worm, I, supported in eccentric bearings. Such bearings may be arranged as shown in Fig. 4, the longer slide being secured to the journal and the shorter to the worm, in the same manner as the stylus is secured, and the worm or screw 1 may now be adjusted so as to swing through a circle the diameter of which is equal to the width of the wave-line. The screw or worm l is turned by means of the crank m, and the styluscarrying arm I) is for the time connected with the worm or screw l by the hinged lever n, provided with a section of a nut or female screw corresponding with the threads on the worm or screw 1. When now, the crank mis turned the tracer-arm will describe a uniform wave-line, and this waveliue will be transferred to the roll or other surface by the tracer or tracers in a diminished or enlarged scale, as the case may be.

0 is a spring arranged to hold the arm n in contact with the screw 1.

In Fig. 5 I have shown an end view of a pantograph engraving-machine with the stylus P attached, by means of the connecting-arm b, to the tracer-arm A. From this illustration and the previous description it will be readily pen ceived that the stylus can be attached with facility to the tracer-arm and be operated directly therefrom.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination, with the connecting-arm b, of the spindlef, provided with a crank and a stylus, the whole arranged so that by turn ing the spindle, when the stylus is held in a fixed place, the pantograph will describe a circle, as set forth.

2. The combination, with the connecting-arm b, of a spindle provided with a crank and a slide, on which the stylus is secured at any desired distance from the axis of the spindle, substantially as and for the purpose set forth.

3. The combination of the spindle f, the eccentric stylus d, and the crank h, with means to connect the same to a pantograph, the whole arranged to describe an accurate circle, as described.

4. The combination, with the connecting-arm I), of a screw or worm mounted in eccentric bearings and connected with the stylus-carrying arm, so that by turning the worm or screw a wave-line will be described or traced by the pantograph.

5. The combination, with the screw or worm I, provided with the crank m, of the arm a, pro vided with guides fitting into the threads of the screw, and connected with a pantogra-ph, so that a wave-line is produced by the turning of the screw or worm, as described.

6. The combination, with the frame K, the screw I, mounted in eccentric bearin gs, so as to swing through a circle larger than its own diameter, of the crank m and means by which a pantograph is secured to the screw and made to trace a wave-line, substantially as and for the purpose set forth.

JOHN HOPE.

\Vitnesses JOSEPH A. MILLER, J. A. MILLER, Jr. 

